The complement system is an important immediate host defense mechanism. However, massive complement activation can be detrimental. There are several acute injury sertings in which complement activation products may contribute to clinical complications, including thermal injury, adult respiratory distress syndrome (ARDS), septic shock and ischemia/reperfusion injury events such as stroke or myocardial infarction. Agents will be tested both for their ability to inhibit complement activation in vitro and for in vivo efficacy in two rat models of complement-mediated inflammation and tissue injury. PROPOSED COMMERCIAL APPLICATION: Agents identified through the studies outlined in this proposal will have potential for the treatment of thermal injury and adult respiratory distress syndrome (ARDS).